More than 250,000 heart valves are replaced worldwide each year due to structural defects such as valve stenosis that may lead to regurgitation. Valve stenosis is a condition where a heart valve is not able to fully open when blood is pumped through the heart because the heart valve leaflets are too stiff or fused together. Valve stenosis creates a narrowed opening that stresses the heart that can cause fatigue and dizziness in a patient. Regurgitation, which is a backward flow of blood, can reduce efficiency in blood pumping and cause the patient fatigue and shortness of breath.
There are currently two major types of valves that can be used for diseased heart valve replacement: a mechanical valve and a bioprosthetic valve. Mechanical valves demonstrate long term durability, but are associated with lifelong anti-coagulant treatments that prevent thrombus formation caused by the contact between a patient's blood and the valve materials. Bioprosthetic heart valves are typically constructed from porcine heart valves or from bovine or porcine pericardium. Bioprosthetic heart valves do not need anticoagulation, but are vulnerable to structural deterioration caused by calcification that results in the narrowing of the valve orifice and/or cusp tearing. As a result, surgeons may use mechanical heart valves for younger patients to avoid the device replacement risks associated with bioprosthetic heart valves. There continues to be a need for a heart valve that can be used for long term implantation.